A desulfurizing reagent (DSR) is any material which, when added to hot metal such as molten iron alloy, reduces the sulfur content thereof. Such materials include diamide lime, calcium oxide, calcium carbonate, calcium fluoride and various carbon forms.
Thus, a calcium-based desulfurizing reagent is a DSR in which the principal constituent is calcium carbide, preferably furnace calcium carbide, and optionally includes, as lesser constituents, diamide lime, carbon, calcium carbonate, calcium fluoride and/or other materials used in treating hot metal.
While calcium carbide can be used from any source, furnace calcium carbide is generally used in desulfurizing procedures for treating hot metal. Furnace calcium carbide is a commercially available carbide which is 70-85%, by weight, CaC.sub.2 and is produced in an electric furnace.
As recovered from the electric furnace, the carbide is in the form of large agglomerations which are generally first broken down into chunks of about 1-2 inches in diameter and then milled in a grinding mill or series of grinding mills, either in a closed or open circuit, into fine particles. The need for the fine particles is a requirement of the metal producers using the DSR in order to assure that the DSR possesses as high a surface area as possible. Therefore, if a method could be found for the formation of fine particulate DSR whereby the particles are more uniform in size, a step forward in the art would be realized.